Thank you for all of the responses. Actually, I haven't lost any daffodils yet--except for a few with virus that were promptly disposed of. I posted the question because I want to avoid losing any. Every year I add more cultivars but I have read in a number of places about daffodils simply not naturalizing like they used to. To me daffodils are the ultimate perennial, easy care bulbs and I was saddened to learn that this is no longer the case. Still, any hints are welcome. I am lacking detailed information, such as 'Goose Green and Dreamlight...have division 9 genes...poeticus cultivars' provided by Linda Wallpe (thank you). I also thought many (not all) daffodils fared well in hot, dry summers but I learned differently. Again, thank you. Sierra foothills, Northern California, where there is a 'Daffodil Hill' about 70 miles south of me that I have yet to visit. More 'refined and unusual hybrids' are on their way to me right now but I have sought out some species to leaven the mix. Perhaps I will have my own Daffodil Hill someday. Rainy, 49 degrees F, winter is finally here.